Comic Sans looks unpleasant to me. Like it's trying to advertise something and lure you in with surface promises that the product can't fulfill. This may be because a lot of spammers use it.
I have to say both the jrod site and the original enbseries site look terrible. I'm not sure I'd trust "graphical enhancements" from people that clearly have no eyeballs, never mind that they look distinctly dodgy (that is, they look malware-ridden).
I guess some people need to find something to do with all those extra CPU and GPU cycles not taken up by console ports though.